RB status as a determinant of response to UCN-01 in non-small cell lung carcinoma

7-Hydroxystaurosporine (UCN-01), a protein kinase inhibitor in clinical development, demonstrates potent antineoplastic activity. To determine whether specific genetic abnormalities would modulate the response to UCN-01, a model of human non-small cell lung carcinoma (NSCLC) cell lines with differential abnormalities of p16CDKN2, RB, and p53 was used for these studies. Cell growth was measured by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay, and cell cycling was studied using flow cytometric analysis of DNA content. Changes in protein levels and phosphorylation were assessed by Western blotting. In cell lines expressing wild-type RB (A549 and Calul), UCN-01 treatment resulted in dose-dependent growth inhibition, arrest of cells in G1, and a reduction of cells in S phase. p16CDKN2-null cells showed similar growth inhibition to normal fetal lung fibroblasts. UCN-01-induced growth arrest was accompanied by induction of p21CDKN1 and a shift of Rb to the hypophosphorylated state in both p53 wild-type and mutant cell lines. In contrast, UCN-01 treatment of the RB-null cell line H596 resulted in less growth inhibition. To test the role of RB in response to UCN-01, effects of treatment were examined in two human isogenic models of RB expression: the bladder cancer cell line 5637 (RB-null) and the prostate cancer cell line DU-145 (RB-mutant). In the Rb-expressing 5637 subline (RB5), UCN-01 treatment resulted in Rb hypophosphorylation and an accumulation in G1 in contrast to the parent line. Similarly, the wild-type Rb-expressing DU-145 sublines (DU1.1 and B5) showed increased G1 arrest compared with the parent cells. We conclude that UCN-01-induced G1 arrest can occur in cells null for p53 and p16CDKN2, and that RB status influences the ability of UCN-01 to induce a G1 arrest. These data suggest that the molecular profile of cell cycle regulating genes in individual tumors may predict responsiveness and provide insight into optimal therapeutic application of this new antineoplastic agent.

Survival of donor leukocyte subpopulations in immunocompetent transfusion recipients: frequent long-term microchimerism in severe trauma patients

We recently reported detection of a transient increase in circulating donor leukocytes (WBCs) in immunocompetent recipients 3 to 5 days posttransfusion (tx) (Blood 85:1207, 1995). We have now characterized survival kinetics of specific donor WBC subsets in additional tx populations. Eight female elective surgery patients (pts) were sampled pre-tx and on days 1, 3, 5, 7, and 14 post-tx. Ten female trauma pts transfused with a total of 4 to 18 U of relatively fresh red blood cells were sampled up to 1.5 years post-tx. WBC subsets from frozen whole blood were isolated using CD4, CD8 (T cell), CD15 (myeloid), and CD19 (B cell) antibody-coated magnetic beads. Donor WBCs were counted by quantitative polymerase chain reaction (PCR) of male-specific sex determining region (SRY) sequences. PCR HLA typing and mixed leukocyte reaction (MLR) between recipient and donor WBCs were performed on two of the trauma tx recipients who had long-term chimerism of donor cells post-tx. In 6 of 8 female surgery pts, circulating CD4(+) male donor cells peaked at day 3 or 5 (0.01 to 1 cell/microL), followed by clearance by day 14. In 7 of 10 female trauma pts, we observed multilineage persistence of male donor WBCs (CD4, CD8, CD15, CD19) for 6 months to 1.5 years post-tx at concentrations of 10 to 100 cells/microL. In 2 trauma recipients studied, MLR showed no, or very low, response to WBC of the single donor implicated as the source of microchimerism by HLA typing. Establishment of long-term multilineage chimerism in trauma recipients is probably caused by engraftment of donor stem cells and mutual tolerance between recipient and donor leukocytes. A better understanding of factors determining clearance versus chimerism of transfused leukocytes is critical to prevention of alloimmunization and transfusion-induced graft-versus-host disease, and, potentially, to induction of tolerance for transplantation.

Platelet-erythrocyte adhesion in sickle cell disease

BACKGROUND

The abnormal adherence of sickle red blood cells (sRBC) to other cell types likely contributes to vaso-occlusion. Increased numbers of platelet-erythrocyte aggregates (PEA) and platelet activation have been described in sickle cell disease. The present study was undertaken to determine the contribution, if any, of the extracellular matrix protein thrombospondin to the adhesion of sRBC and platelets.

METHODS

Platelet activation and PEA were measured using fluorescent-labeled monoclonal antibodies and flow cytometry. Platelet red-cell adhesion was measured by a gravity sedimentation assay. Erythrocyte-bound thrombospondin (TSP) was determined by enzyme-linked immunoabsorbant assay (ELISA).

RESULTS

Our studies demonstrate significant platelet activation and adhesion of sRBC to platelets in sickle cell disease. Thrombospondin was detected on sRBC. There was variable inhibition of sRBC-platelet adhesion by antibodies to CD36 (thrombospondin receptor) and antibodies to thrombospondin.

CONCLUSIONS

Thrombospondin on sRBC may mediate, at least in part, sRBC-platelet adhesion in sickle cell disease. The study of heterotypic cell-cell interactions is important in understanding the pathogenesis of vaso-occlusion in sickle cell disease.

Platelet activation in patients with sickle cell disease

Vascular occlusion and vasculopathy underlie much of the morbidity in patients with sickle cell anaemia. Platelets may play a role in this vasculopathy. Samples from 43 patients with sickle cell disease (SCD) were examined for evidence of platelet activation using fluorescent-labelled monoclonal antibodies and flow cytometry. There was increased expression of activation-dependent antigens on the platelets from patients with SCD compared to those from both Caucasian and African-American controls. In addition, SCD patients had increased levels of platelet microparticles. Platelets are activated in patients with sickle cell disease. The contribution of platelet activation to sickle cell pathophysiology is under active investigation in our laboratories.

Platelet activation and platelet-erythrocyte aggregates in patients with sickle cell anemia

Vascular occlusion and vasculopathy underlie much of the morbidity in patients with sickle cell anemia. Platelets may play a role in this vasculopathy. Samples from 12 adults patients with sickle cell anemia were examined for evidence of platelet activation and formation of platelet-erythrocyte aggregates (PEA) using fluorescent-labeled monoclonal antibodies and flow cytometry. We noted an increased expression of activation-dependent antigens on the platelets from patients with sickle cell anemia compared with those from both white and black control subjects. In addition, patients with sickle cell anemia had increased levels of platelet microparticles and PEA. Platelets are activated in patients with sickle cell anemia and they adhere to sickle erythrocytes. The significance of this activation and adherence are the subject of further investigation.

Thrombopoietin is synergistic with other hematopoietic growth factors and physiologic platelet agonists for platelet activation in vitro

Thrombopoietin (TPO) is the primary physiologic regulator of platelet production. The effect of TPO on platelet function, both alone and in combination with other hematopoietic growth factors, adenosine diphosphate (ADP), and epinephrine, was investigated using fluorescent-labeled antibodies to the activation-dependent antigen CD62 (P-selectin) and flow cytometry. TPO stimulated CD62 expression on normal human platelets, and this expression was completely inhibited by the soluble extracellular domain of the TPO receptor, MPL. The growth factors granulocyte colony-stimulating factor (G-CSF) and erythropoietin (EPO), but not interleukin-3 (IL-3) or stem-cell factor (SCF), also stimulated platelet activation. The combination of EPO, SCF, ADP, and epinephrine with TPO were synergistic for platelet CD62 expression. These data further support a role for TPO in modulating platelet function.

Physiologic concentrations of arginine vasopressin activate human platelets in vitro

Arginine vasopressin (AVP) is a neurohypophyseal peptide hormone with protean effects. Previous reports had shown that AVP stimulates platelets, but only at concentrations 3-6 logs higher than the normal plasma concentrations in humans. In this study we tested the hypothesis that AVP, at physiologic concentrations, stimulated the expression of an activation-dependent platelet antigen. Platelets obtained from normal volunteers were incubated with increasing concentrations of AVP and the expression of the activation-dependent platelet antigen P-selectin (CD62) was determined by monoclonal antibodies and flow cytometry. There was a concentration-dependent increase in CD62 expression with increasing AVP concentration; at 1 pm AVP, 24.5% (1.3-88.5%) [median (range)] of platelets expressed CD62. The selective vasopressin V1 receptor antagonist d(CH2)(5)-Tyr(me)AVP (TM-AVP) completely abolished AVP-stimulated CD62 expression. We conclude that AVP can activate platelets at concentrations found in normal humans, at least in vitro, and that this response is mediated by the platelet V1 receptor. AVP may be a physiologic platelet agonist.

Screening of blood donors for idiopathic CD4+ T-lymphocytopenia

BACKGROUND

The recent recognition of idiopathic CD4+ T-lymphocytopenia (ICL) had led to concern that an unknown immunodeficiency virus may be transmissible by transfusion.

STUDY DESIGN AND METHODS

To evaluate the prevalence and significance of low CD4+ values among blood donors, CD4+ data on 2030 blood donors who were negative for antibody to human immunodeficiency virus type 1 (HIV-1) were compiled. Those with CD4+ values below ICL cutoffs (< 300 CD4+ T cells/microL, or < 20% CD4+ T cells) were recalled for follow-up investigations. Serial CD4+ data on 55 homosexual men who seroconverted during prospective follow-up and data on 139 anti-HIV-1-positive blood donors initially evaluated in 1986 were reviewed as well.

RESULTS

Five seronegative donors (0.25%) had absolute CD4+ counts < 300 cells per microL and/or < 20 percent. On follow-up, all five donors had immunologic findings within normal ranges, lacked HIV risk factors, and tested negative for HIV types 1 and 2 and human T-lymphotropic virus type I and II infections by antibody and polymerase chain reaction assays. Four of five donors reported transient illness shortly after their low CD4+ count donations. The median interval from HIV-1 seroconversion to an initial CD4+ value below ICL CD4+ cutoffs was 63 months for infected homosexual men. Of 139 HIV-1-infected blood donors studied 1 to 2 years after seropositive donations, 34 (24%) had CD4+ counts < 300 cells per microL and/or < 20 percent.

CONCLUSION

Low CD4+ counts are rare among anti-HIV-1-negative volunteer blood donors and are generally associated with transient illnesses. If any unknown virus progresses similarly to HIV-1, CD4+ count donor screening would be a poor surrogate for its detection.

Prolonged circulation of activated platelets following plasmapheresis

The extent and duration of in vivo platelet activation were determined in 12 volunteer donors undergoing automated plasmapheresis. Expression of P-selectin, activated GpIIb/IIIa, and platelet microparticle formation were measured by flow cytometry on peripheral blood samples obtained immediately before and after plasmapheresis and at 24 hour intervals thereafter for up to 3 days. Although no adverse effects were noted in any donor, immediately after apheresis 3-87% of circulating platelets expressed P-selectin; by 48 hours, 0.5-50% expressed P-selectin; and by 72 hours, all donors studied had fewer than 5% P-selectin expression on circulating platelets. Results were similar for the expression of the activated conformation of GpIIb/IIIa. There was a positive correlation with in vitro P-selectin expression in response to ADP in the pre-apheresis sample and the number of platelet microparticles detected in the donor following plasmapheresis. In addition, the percent expression of P-selectin and activated GpIIb/IIIa in response to ADP was reproducible in each individual studied on five separate occasions (CV < or = 8%). Platelets activated during plasmapheresis using an automated device may circulate for at least 48 hours, and pre-plasmapheresis response of platelets to the agonist ADP correlated with platelet microparticle formation post-plasmapheresis.

Peripheral-blood mononuclear cell responses to recombinant hepatitis C virus antigens in patients with chronic hepatitis C

Peripheral blood mononuclear cell proliferative responses in vitro to recombinant yeast or Escherichia coli hepatitis C virus fusion proteins were evaluated in 20 patients with chronic hepatitis C who were reactive for antibody to hepatitis C virus (on enzyme immunoassay, version 2.0, and a four-antigen recombinant immunoblot assay). Twenty age-matched, healthy individuals negative for antibody to hepatitis C virus were used as a control group. Peripheral-blood mononuclear cells from all chronic hepatitis C patients with antibodies to hepatitis C virus antigens c22 and c100-3 proliferated in vitro in response to the corresponding recombinant hepatitis C virus fusion protein. Peripheral-blood mononuclear cells from 75% of patients infected with hepatitis C virus proliferated in response to cytidine monophosphate-keto-3-deoxyoctulosonic acid-core recombinant antigen but there was no proliferative response to cytidine monophosphate-keto-3-deoxyoctulosonic acid-EF (derived from the NS5 region). All hepatitis C virus-infected patients had 33c antibody, but peripheral-blood mononuclear cells from only 9 of 14 (64%) proliferated in vitro in response to 33c. Ninety-five percent of all hepatitis C virus-infected patients had peripheral-blood mononuclear cells that proliferated in response to at least one recombinant hepatitis C virus fusion protein. The numbers and percentages of CD3 T cells, CD19 B cells and natural killer cells from patients with chronic hepatitis C virus infection did not differ from those in the healthy control group. However, the number of non-major histocompatibility complex-restricted cytotoxic T cells (CD3-positive, CD56-positive, CD16-positive) was increased in patients with chronic hepatitis C virus infection (p < 0.05).

Removal by white cell-reduction filters of activated platelets expressing CD62

White cell (WBC)-reduction filters that remove more than 99 percent of the WBCs from platelet concentrates are rapidly being introduced into routine use. Using activation-dependent monoclonal antibodies and flow cytometry, platelet activation was evaluated before and after WBC reduction in 10 platelet concentrates prepared manually from whole blood obtained from five male and five female regular volunteer blood donors. In general no significant increases were found in platelet activation markers after WBC reduction using filters. However, if platelets were activated during preparation, increased numbers of platelets were found expressing the activation marker CD62, and this correlated with the decrease in the platelet count after WBC reduction. These observations may explain increased platelet loss following WBC reduction in some platelet components.

Factors affecting the in vitro evolution of a myeloma cell line

A continuously growing plasma cell line has been established from the bone marrow of a multiple myeloma patient. Initial growth of the cells was dependent on the presence of bone marrow stromal cells. Following initial outgrowth the cells were maintained by transfer onto non-autocthonous bone marrow stromal cultures. Following approximately one year of continuous growth, a subline was derived which could be grown independently of feeder cells. These stromal-cell-independent myeloma cells nevertheless retained dependence for a growth factor present in stromal-cell-conditioned media. The relevant factor in the conditioned media was determined to be interleukin-6 (IL-6). The cells also ultimately became independent of the conditioned media. These latter cells were shown to contain mRNA for IL-6 and eventually began to secrete IL-6. This cell line has thus progressed from complete dependence on stromal cells to IL-6-dependent growth in the absence of stromal cells to complete self sufficient growth. This in vitro progression may reflect an in vivo pattern of myeloma development.

Detection of plasmapheresis-induced platelet activation using monoclonal antibodies

Twelve volunteer plasma donors were studied so as to determine the extent and duration of in vivo platelet activation caused by automated plasmapheresis. Samples obtained immediately before and after donation were mixed with murine monoclonal antibodies PAC-1 and S12, which bind specifically to activated platelets. Antibody binding on platelets was quantitated by flow cytometry. The change in the mean fluorescence intensity (MFI) (MFI after donation minus MFI before donation) was 61 +/- 23 (confidence interval [CI], 48-75) for PAC-1 and 56 +/- 64 (CI, 19-92) for S12 in plasmapheresis donors, as compared to 0.3 +/- 0.8 (PAC-1; CI, -0.2-0.8) and 0.3 +/- 0.9 (S12: CI, -0.3-0.9) in whole blood donors (p less than 0.05). Additional studies showed circulating activated platelets up to 48 hours after plasmapheresis. In contrast to other data, significant platelet activation was demonstrated following plasmapheresis on an automated machine. None of the donors had clinical complications. Nevertheless, it may be appropriate to delay subsequent plasmapheresis and platelet procurement from such donors until evidence of platelet activation has disappeared.

Abnormalities in immune regulation precede the development of multiple myeloma

Immunosuppression of immunoglobulin synthesis seen in patients with multiple myeloma is in part due to immunosuppressive CD5 positive B cells. In a 13 year longitudinal study of an IgA-deficient blood donor who developed multiple myeloma, the presence of immunosuppressive CD5 positive B cells and T cells preceded the diagnosis of overt multiple myeloma and the appearance of immunosuppressive monocytes. These data argue that certain immune defects may be involved in the development of myeloma and are not simply a consequence of overt malignancy.

CD5 positive immunoregulatory B cells in spleen populations from multiple myeloma patients

CD19+CD5+ lymphocytes constitute a minority of peripheral blood B cells. In view of the importance of these cells in the pathogenesis of the immunoregulation of myeloma, their incidence in another lymphoid organ was determined. CD5+ B cells were studied in 9 spleens from patients with multiple myeloma and in 10 spleens from normal individuals removed secondary to trauma. The total number of CD19+ B cells were increased in myeloma spleens (44.4% +/- 12.6%) as compared to normal spleens (20.4% +/- 7.4%). Likewise, the percentage of CD19 cells which co-expressed CD5 were increased in myeloma (25.3% +/- 12.4%) versus normal (4.4% +/- 2.3%) spleen. CD5+ B cells isolated from myeloma spleens, but not normal spleens, inhibit production of immunoglobulin in a pokeweed mitogen driven assay. Thus the spleen appears to be an important source of immunoregulatory B cells in multiple myeloma.

CD5 positive immunoregulatory B cell subsets

B-chronic lymphocytic leukemia (B-CLL) is a heterogeneous disease often expressed as a clonal expansion of CD5+ B cells. We report the characterization of CD5+ B cells from two unique B-CLL patients. Cells from patient 1 coexpressed CD5 (leu-1), CD19 (Leu-12), CD20 (B1), and HLA-DR; they were CD10 (J5), CD21 (B2), CD22 (Leu-14), CD25 (IL2-R1), PCA-1, surface, and cytoplasmic Ig negative. They suppressed normal peripheral blood lymphocyte (PBL) pokeweed mitogen (PWM) -stimulated immunoglobulin (Ig) synthesis greater than 80%. Cells from patient 2 were CD5 (Leu-1), CD19 (Leu-12), CD20 (B1), CD21 (B2), CD22 (Leu-14), HLA-DR, IgM, and kappa positive. They were negative for CD10 (J5), CD25 (IL2-R1), and PCA-1. These cells did not suppress normal PBL PWM-stimulated Ig synthesis but produced a monoclonal IgM kappa protein with rheumatoid factor-like activity. These observations suggest that there are different CD5+ B cell subsets, one immunosuppressive and the other autoreactive.

Effects of plasmapheresis on peripheral blood mononuclear cell populations from patients with macroglobulinemia

Effects of plasmapheresis on peripheral blood T-cell, B-cell, monocyte, and natural-killer-cell populations were studied in ten macroglobulinemia patients with hyperviscosity syndrome. Following plasmapheresis, there was a transient decrease in the number of T4+ helper cells and a longer-lasting decrease in the number of Leu-7+ natural killer cells and Mo2+ monocytes. In addition, there was a greater than 50% decrease in the in vitro ingestion capacity of monocytes. Although no significant changes in the numbers of IgM+, B1+, B4+, or PCA+ B cells (P greater than .05) were detected, there was a highly significant (P less than .01) increase in I2 antigen density on the surface of IgM+ B cells and in the bromodeoxyuridine uptake by these cells 7-9 days after plasmapheresis. These findings suggest that following plasmapheresis, IgM+ B cells are activated. Using flow cytometry to determine when maximum IgM+ B cell activation occurs by measuring I2 antigen density on the cell surface may be useful in determining the postplasmapheresis timing of chemotherapy in macroglobulinemia patients with hyperviscosity syndrome who require more aggressive treatment.

Marshall-Smith syndrome: two case reports and a review of pulmonary manifestations

Two patients with the Marshall-Smith syndrome are described. Both had significant and fatal respiratory distress attributable to this condition. Congenital, functional, and acquired abnormalities of the respiratory tract are described in nine of the 11 case reports in the literature and are characteristic of this syndrome as well as a primary cause of failure to thrive and death in these patients. Unusual immunologic findings in one of our two patients are the first to be reported in the Marshall-Smith syndrome. Quantitation of immune function in other patients with this condition will be helpful in determining the significance of these results. It is hoped that the etiology of the syndrome will be discovered as more cases are recognized and reported by pediatricians caring for infants with failure to thrive, advanced bone age, and chronic respiratory symptomatology.

Coccidioidomycosis: early immunologic findings

T and B lymphocyte number and lymphocyte response to phytohemagglutinin, pokeweed mitogen, concanavalin A, coccidioidin and streptokinase-streptodornase (SKSD), plus monocyte ingestion of coccidioidin- and IgG-coated chicken erythrocytes were measured in 5 patients with coccidioidal meningitis, 11 with nonmeningeal extrapulmonary cocidioidomycosis and 5 with localized pulmonary infections. These cases were evaluated within six months of the onset of infection. Lymphocytic responses to phytohemagglutinin, pokeweed mitogen, concanavalin A, SKSD and coccidioidin and monocytic ingestion of coccidioidin- and IgG-coated chicken erythrocytes were severely decreased in patients with meningeal and nonmeningeal, extrapulmonary coccidioidomycosis but not in patients with localized pulmonary infections. T and B cell numbers, however, were normal in all groups. Thus, defects in cellular immunity are involved in the pathogenesis of extrapulmonary coccidioidomycosis and measurements of lymphocytic and monocytic function may identify patients prone to extrapulmonary infection.

A human plasma cell line: induction and characterization

A stable line of IgG K producing human plasma cells was established from a myelomatous human bone marrow using conditioned media from a rapidly metabolizing lymphoblast line, RPMI 4098. Growth in RPMI 1640 (15% fetal calf serum) at 6% CO2 promoted a 62-hour doubling time with a preferred cell concentration of 1 x 10(6)/mL. Surface marker studies showed: no receptors for sheep erythrocytes, no surface immunoglobulins, variable number of cells bearing complement receptors and 83% bearing Fc receptors. Although transmission electron micrographs demonstrated a poorly developed endoplasmic reticulum, radioimmunoassay showed 23 ng IgG and 28.7 ng Kappa were produced by 1 x 10(6) cells in 72 hours. Further, the cells are lipase, esterase and Epstein-Barr nuclear antigen negative. ASG banding showed a total chromosome number that varied from 46--49. Since the number of human plasma cell lines is limited, it is felt that this line will augment the immunobiological study of human myeloma.

Multiple myeloma: an immunologic profile. Cytotoxic and suppressive effects of the EA rosette-forming cell

Lymphoid cells bearing receptors for human IgG anti-Rh antibody but not otherwise identifiable as T or B cells were isolated from the peripheral blood of human multiple myeloma patients. These cells do not demonstrate surface immunoglobulin, do not secrete immunoglobulin in culture after stimulation with pokeweed mitogen, and do not possess receptors for the third component of complement. They do not form rosettes with sheep erythrocytes, and do not respond to known T cell mitogens. These cells are not phagocytic and do not possess demonstrable nonspecific esterase. Thus, they must be considered at present, members of the "third population" lymphoid cells. These cells are active in the cytotoxic response by myeloma peripheral blood lymphocytes to myeloma plasma cells accounting for approximately 60% of such activity. They are also responsible for part of the suppression of pokeweed mitogen-stimulated immunoglobulin production, and at equivalent suppressor to target cell ratios are more active than immunoregulatory monocytes. Thus, these cells play an important, not previously widely appreciated role in the pathophysiology of the human myeloma patient.

Multiple myeloma: an immunologic profile. Cytotoxic and suppressive effects of the EA rosette-forming cell

Lymphoid cells bearing receptors for human IgG anti-Rh antibody but not otherwise identifiable as T or B cells were isolated from the peripheral blood of human multiple myeloma patients. These cells do not demonstrate surface immunoglobulin, do not secrete immunoglobulin in culture after stimulation with pokeweed mitogen, and do not possess receptors for the third component of complement. They do not form rosettes with sheep erythrocytes, and do not respond to known T cell mitogens. These cells are not phagocytic and do not possess demonstrable nonspecific esterase. Thus, they must be considered at present, members of the "third population" lymphoid cells. These cells are active in the cytotoxic response by myeloma peripheral blood lymphocytes to myeloma plasma cells accounting for approximately 60% of such activity. They are also responsible for part of the suppression of pokeweed mitogen-stimulated immunoglobulin production, and at equivalent suppressor to target cell ratios are more active than immunoregulatory monocytes. Thus, these cells play an important, not previously widely appreciated role in the pathophysiology of the human myeloma patient.

In vitro cytotoxic response to human myeloma plasma cells by peripheral blood leukocytes from patients with multiple myeloma and benign monoclonal gammopathy

Peripheral blood leukocytes (PBL) from myeloma patients were studied for their capacity to lyse plasma cells from myeloma patients, benign monoclonal gammopathy (BMG) patients, and nonneoplastic disease patients. Plasma cells were isolated from bone marrow, labeled with 51Cr, and cultured with PBL isolated from patients with myeloma, BMG, or nonneoplastic disease, as well as normal individuals. PBL from patients with multiple myeloma demonstrated responses to autologous or allogeneic myeloma plasma cells. Optimum conditions for cytotoxic response included a responder-to-stimulator ratio of 1:1 and an effector-to-target ratio of 20:1. PBL from normal individuals or patients with BMG failed to demonstrate this response. However, PBL from BMG patients, but not normal individuals, could be induced to kill myeloma plasma cells (but not nonmyeloma plasma cells) by simultaneous stimulation with allogeneic lymphocytes and myeloma plasma cells.

Multiple myeloma: an immunologic profile. II. Bone marrow studies

Bone marrow mononuclear cell populations were studied in 35 patients without myeloma, 39 patients with multiple myeloma, and 15 patients with benign monoclonal gammopathy. Bone marrow mononuclear cell receptors, responses to mitogens or allogeneic stimuli, and suppressive effects on in vitro peripheral blood lymphocyte (PBL) function were studied. In bone marrow cell populations from patients with untreated multiple myeloma, the percent of complement receptor-bearing cells and the pokeweed mitogen- and concanavalin A-stimulated responses were significantly greater than were those in bone marrow cell populations from patients without myeloma. Sheep red blood cell receptor-bearing cells were significantly greater in marrow populations from treated multiple myeloma patients compared to those from untreated multiple myeloma patients. Sheep red blood cell receptor-bearing cells from the bone marrow of multiple myeloma patients suppressed responses of the multiple myeloma patients' PBL's to autologous mitomycin C-treated bone marrow plasma cells and to allogeneic stimuli in one-way mixed leukocyte culture. Complement receptor-bearing cells suppressed the response to pokeweed mitogen. The presence of lymphocytes in the marrow compartment that are capable of suppressing the response of myeloma patients' PBL's to plasma cell antigens may be significant in the pathogenesis of multiple myeloma.

Studies on the pathogenesis of an immune defect in multiple myeloma

The reduced capacity of patients with multiple myeloma to respond to antigen challenge is well recognized. Response to antigen involves antigen recognition, cell proliferation, and synthesis and secretion of antibody. This study examines this sequence of events in peripheral blood lymphocytes from untreated and treated patients with myeloma, from individuals with benign monoclonal gammopathy, and from normal healthy donors. Antigen-binding capacity was assessed by testing the ability of lymphocytes to bind radio-labeled pneumococcal polysaccharide, tetanus toxoid, or diptheria toxin. The in vitro proliferative response to these antigens as well as to pokeweed mitogen and streptokinase-streptodornase was evaluated. The secretion of immunoglobulin in response to pneumococcal polysaccharide, tetanus toxoid, and pokeweed mitogen by 2-4 x 10(6) lymphocytes in 7-day cultures was determined. The effects of coculture of myeloma peripheral blood lymphocytes and normal peripheral blood lymphocytes on immunoglobulin production and mixed leukocyte reactions were explored. All myeloma patients had normal numbers (3-8/5,000 cells) of antigen-binding cells. However, most showed a diminished antigen-induced blast transformation as measured by uptake of [(125)I]5-iodo-2'-deoxyuridine in culture. Immunoglobulin production in response to specific antigen in myeloma lymphocytes was 30-80% less than in normal lymphocytes. Immunoglobulin synthesis and mixed leukocyte responses by normal peripheral blood lymphocytes could be suppressed by myeloma lymphocytes. Multiple suppressor populations were present. Thus, the immune defect in myeloma is beyond the antigen recognition step and involves both the proliferation of antigen-sensitive cells and immunoglobulin production. Further suppressive effects are imposed on normal cells, implying defects in immunoregulation in this disease.

Multiple myeloma: an immunologic profile. I. Peripheral blood studies

Seventy-four patients with multiple myeloma, 17 untreated and 57 treated, were studied to characterize their peripheral blood lymphocytes. PBL were studied for E, EAC, and EA rosette-forming cells, SIg, and Fc receptor-bearing cells. The responses to HA, Con A, and PWM were assessed as well as their ability to stimulate or to respond in a MLC. Finally, the capacity of mitogen-stimulated lymphocytes to lyse Chang cells, CRBC, and PHA-stimulated lymphoblasts was examined. These results were compared with a group of normals and patients with benign monoclonal gammopathy. In untreated myeloma patients there was a normal percentage of T cells, but an abnormal distribution of B cells as judged by a decrease in SIg-bearing cells, as well as an increase in EAC rosette-forming cells. Subpopulation analysis showed a marked increase in EAC rosette-forming cells without SIg. PHA, Con A, and PWM, and response in MLC were all normal. However, the ability to stimulate in MLC was significantly depressed. Treated myeloma patients had similar findings, except that the response to PWM was significantly depressed. The capacity of PWM-stimulated cells to lyse target cells was depressed in both groups. The results indicate that, in the peripheral blood of myeloma patients, there are populations of lymphocytes characterized by the presence of the EAC receptor without SIg, which are deficient in the capacity to stimulate an MLC response and the ability to be cytotoxic when stimulated by PWM. The results form a baseline for the study of abnormal lymphoid function in human myeloma.